Bragg Grating Sensor
Mostrando 1-12 de 16 artigos, teses e dissertações.
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1. Case study of muscle fatigue in parafunctional patient using occlusal device with fiber Bragg grating sensors
Abstract This case study describes a new method using a fiber optic Bragg grating sensor to determine muscle fatigue in a patient wearing a resilient occlusal device for the treatment of bruxism symptoms. Four tasks performed at maximum bite force induced rapid exhaustion for the analysis of fatigue. The results show that it is possible to obtain a better un
J. Microw. Optoelectron. Electromagn. Appl.. Publicado em: 2018-06
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2. Influence of temperature on the refractive index sensitivities of fiber Bragg gratings refractometers
Abstract Effect of cross-sensitivity between temperature and refractive index (RI) was studied using an optical sensor based on Bragg grating inscribed in an etched multi-mode fiber (MMF). RI sensitivities of different modes were used to obtain a linear response and temperature dependence in water:glycerin solutions. Results pointed out that the absolute ave
J. Microw. Optoelectron. Electromagn. Appl.. Publicado em: 2017-04
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3. Analysis of Thermo-Mechanical Stress in Fiber Bragg Grating Used for Hydro-Generator Rotor Temperature Monitoring
Abstract Fiber Bragg gratings (FBGs) offer new possibilities to monitor accurately the rotor temperature. Dozens of sensors can be mounted in series in a single fiber and used to measure the temperature in several points of the rotor winding. Such sensors installed directly on the rotor winding surface are thermally isolated from the cooling air by a silicon
J. Microw. Optoelectron. Electromagn. Appl.. Publicado em: 2017-04
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4. Long Period Bragg Grating in Coaxial Transmission Lines
This work shows the utilization of a coaxial cable for the fabrication of a long period Bragg grating. The grating is fabricated removing the dielectric in short pieces of the cable so that the discontinuities account for the variation in the medium refractive index. Simulated and experimental results of the grating resonances are shown as a function of the
J. Microw. Optoelectron. Electromagn. Appl.. Publicado em: 2015-06
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5. Etched FBG written in multimode fibers: sensing characteristics and applications in the liquid fuels sector
AbstractIn this work, a refractometric fiber sensor for the liquid fuels sector is described. The use of etched FBGs produced in multimode fibers is proposed to overcome the drawbacks associated with sensing high refractive index samples employing fiber transducers. The transducer sensitivity can be tailored by adjusting the final diameter of the etched Brag
J. Microw. Optoelectron. Electromagn. Appl.. Publicado em: 2015-06
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6. Hardware embedded fiber sensor interrogation system using intensive digital signal processing
The description of an interrogation system for fiber Bragg grating sensors is reported. The full implementation in hardware of the required signal processing is proposed and made publicly available. The hardware description is implemented in a field programmable gate array (FPGA) development kit and the processing units allow one to control an optoelectronic
J. Microw. Optoelectron. Electromagn. Appl.. Publicado em: 2014-12
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7. A technique to package Fiber Bragg Grating Sensors for Strain and Temperature Measurements
This paper reports an effective method of packaging a fiber Bragg grating (FBG) for the simultaneous measurement of temperature and strain. The technique consists of embedding two fiber Bragg grating sensors inside a polymeric material with different geometrical characteristics. The mechanical and thermal characterizations of the optical transducer were perf
J. Microw. Optoelectron. Electromagn. Appl.. Publicado em: 2013-12
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8. Performance analysis of peak tracking techniques for fiber Bragg grating interrogation systems
In this paper, we propose a spectral correlation-based technique for tracking the wavelength shift of a fiber Bragg grating. We compared this approach, by means of a Monte Carlo numerical simulation, to the typical peak tracking techniques applied in classic interrogation systems. As result, we obtained a considerable gain in terms of noise tolerance (about
J. Microw. Optoelectron. Electromagn. Appl.. Publicado em: 2012-12
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9. APLICAÇÃO DE MATERIAIS COM MAGNETOSTRICÇÃO GIGANTE EM SENSORES DE DESLOCAMENTO SEM CONTACTO / GIANT MAGNETOSTRICTIVE MATERIALS APPLIED TO CONTACTLESS DISPLACEMENT SENSORS
Magnetostriction is a property of ferromagnetic materials to deform in the presence of a magnetic field. Magnetostriction is an inherent property of magnetic materials, which is unchangeable with time. Materials exhibiting strains in the order of 10-3 are known as giant magnetostrictive materials (GMM).In this dissertation we study the application of these m
Publicado em: 2007
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10. ANÁLISE DA CALIBRAÇÃO DE SENSORES A REDE DE BRAGG EM FIBRAS ÓPTICAS INTERROGADOS ATRAVÉS DA TÉCNICA DE FILTROS FIXOS / ANALYSIS OF THE CALIBRATION TO BRAGG GRATING SENSORS IN FIBER OPTICS INTERROGATED TROUGHT FIXED FILTERS TECHNIQUE
Nesse trabalho, descreve-se o desenvolvimento de uma calibração do sistema de interrogação dos espectros das redes de Bragg baseando-se em uma simulação numérica adotada de testes experimentais. O objetivo é calibrar a técnica de demodulação óptica utilizando dois filtros de transmissão fixos, procurando-se principalmente a posição verdadeira
Publicado em: 2007
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11. APPLICATIONS OF FIBER BRAGG GRATING SENSORS IN THE MEASUREMENT OF PH AND OF STRAIN IN HARD THIN FILMS / APLICAÇÕES DE SENSORES A REDE DE BRAGG EM FIBRAS ÓPTICAS NA MEDIÇÃO DE PH E DEFORMAÇÃO DE FILMES FINOS DE ALTA DUREZA
Este trabalho versa sobre duas diferentes aplicações de sensores a redes de Bragg em fibra óptica. A primeira consiste no desenvolvimento de uma técnica de sensoriamento do pH empregando fibra óptica, que visa a monitoração contínua e permanente deste parâmetro em poços de petróleo depletados e de injeção. Nesta aplicação, as redes de Bragg s�
Publicado em: 2006
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12. EFFECTS AND APPLICATIONS OF NON-HOMOGENEOUS STRAINS IN BRAGG GRATINGS / EFEITOS E APLICAÇÕES DE DEFORMAÇÕES NÃO HOMOGÊNEAS EM REDES DE BRAGG
Fiber Bragg gratings (FBG) are modulations in the effective refractive index of optical fibers, introduced in a small length along the fiber core. Such components operate as narrow band reflective filters, that is, when illuminated by a broad-band light source, they reflect a narrow spectral band centered at a specific wavelength, the Bragg wavelength. This
Publicado em: 2005